{"id":"https://openalex.org/A5113597471","orcid":null,"observed_orcids":[],"display_name":"Kazuyuki Koyama","raw_author_names":["Kazuyuki KOYAMA","Kazuyuki Koyama"],"full_name":"Kazuyuki KOYAMA","works_count":24,"cited_by_count":311,"summary_stats":{"2yr_mean_citedness":2.0,"h_index":11,"i10_index":11},"ids":{"openalex":"https://openalex.org/A5113597471","orcid":null,"observed_orcids":[]},"affiliations":[{"institution":{"id":"https://openalex.org/I145673806","ror":"https://ror.org/046f6cx68","display_name":"Fujita Health University","country_code":"JP","type":"education","lineage":["https://openalex.org/I145673806"]},"years":[2006]},{"institution":{"id":"https://openalex.org/I205349734","ror":"https://ror.org/02e16g702","display_name":"Hokkaido University","country_code":"JP","type":"education","lineage":["https://openalex.org/I205349734"]},"years":[1999]},{"institution":{"id":"https://openalex.org/I4210091314","ror":"https://ror.org/00jy2zq62","display_name":"Gifu Prefectural Tajimi Hospital","country_code":"JP","type":"healthcare","lineage":["https://openalex.org/I4210091314"]},"years":[2012,2011,2010,2009,2008,2005]},{"institution":{"id":"https://openalex.org/I4210120269","ror":"https://ror.org/02v50dx14","display_name":"Taiho Pharmaceutical (Japan)","country_code":"JP","type":"company","lineage":["https://openalex.org/I4210120269"]},"years":[1991,1989]},{"institution":{"id":"https://openalex.org/I4210162198","ror":"https://ror.org/05gtpxs59","display_name":"Aichi Prefectural Government","country_code":"JP","type":"government","lineage":["https://openalex.org/I4210162198"]},"years":[1996]},{"institution":{"id":"https://openalex.org/I4405255783","ror":"https://ror.org/03dzfh113","display_name":"Shin-yurigaoka General Hospital","country_code":"JP","type":"healthcare","lineage":["https://openalex.org/I4405255783"]},"years":[2024]},{"institution":{"id":"https://openalex.org/I4405275510","ror":"https://ror.org/03qt4xn36","display_name":"Meiji Seika Pharma Co., Ltd. (Japan)","country_code":"JP","type":"company","lineage":["https://openalex.org/I4405275510"]},"years":[1999]},{"institution":{"id":"https://openalex.org/I60134161","ror":"https://ror.org/04chrp450","display_name":"Nagoya University","country_code":"JP","type":"education","lineage":["https://openalex.org/I60134161"]},"years":[1999]}],"last_known_institutions":[{"id":"https://openalex.org/I4405255783","ror":"https://ror.org/03dzfh113","display_name":"Shin-yurigaoka General Hospital","country_code":"JP","type":"healthcare","lineage":["https://openalex.org/I4405255783"]}],"topics":[{"id":"https://openalex.org/T11389","display_name":"Maternal and fetal healthcare","count":11,"subfield":{"id":"https://openalex.org/subfields/2735","display_name":"Pediatrics, Perinatology and Child Health"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}},{"id":"https://openalex.org/T10989","display_name":"Uterine Myomas and Treatments","count":7,"subfield":{"id":"https://openalex.org/subfields/2729","display_name":"Obstetrics and Gynecology"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}},{"id":"https://openalex.org/T11589","display_name":"Gynecological conditions and treatments","count":5,"subfield":{"id":"https://openalex.org/subfields/2729","display_name":"Obstetrics and Gynecology"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}},{"id":"https://openalex.org/T12096","display_name":"Ectopic Pregnancy Diagnosis and Management","count":4,"subfield":{"id":"https://openalex.org/subfields/2729","display_name":"Obstetrics and Gynecology"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}},{"id":"https://openalex.org/T10307","display_name":"Head and Neck Cancer Studies","count":2,"subfield":{"id":"https://openalex.org/subfields/2733","display_name":"Otorhinolaryngology"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}}],"topic_share":[{"id":"https://openalex.org/T12096","display_name":"Ectopic Pregnancy Diagnosis and Management","value":6.13e-05,"subfield":{"id":"https://openalex.org/subfields/2729","display_name":"Obstetrics and Gynecology"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}},{"id":"https://openalex.org/T11389","display_name":"Maternal and fetal healthcare","value":5.46e-05,"subfield":{"id":"https://openalex.org/subfields/2735","display_name":"Pediatrics, Perinatology and Child Health"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}},{"id":"https://openalex.org/T10989","display_name":"Uterine Myomas and Treatments","value":3.95e-05,"subfield":{"id":"https://openalex.org/subfields/2729","display_name":"Obstetrics and Gynecology"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}},{"id":"https://openalex.org/T12193","display_name":"Trigeminal Neuralgia and Treatments","value":3.2e-05,"subfield":{"id":"https://openalex.org/subfields/2728","display_name":"Clinical Neurology"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}},{"id":"https://openalex.org/T13437","display_name":"Mechanisms of cancer metastasis","value":2.08e-05,"subfield":{"id":"https://openalex.org/subfields/1312","display_name":"Molecular Biology"},"field":{"id":"https://openalex.org/fields/13","display_name":"Biochemistry, Genetics and Molecular Biology"},"domain":{"id":"https://openalex.org/domains/1","display_name":"Life Sciences"}}],"x_concepts":[{"id":"71924100","wikidata":"https://www.wikidata.org/wiki/Q11190","display_name":"Medicine","score":0.9840653538703918},{"id":"86803240","wikidata":"https://www.wikidata.org/wiki/Q420","display_name":"Biology","score":0.7003807425498962},{"id":"141071460","wikidata":"https://www.wikidata.org/wiki/Q40821","display_name":"Surgery","score":0.6338076591491699},{"id":"126322002","wikidata":"https://www.wikidata.org/wiki/Q11180","display_name":"Internal medicine","score":0.5948107838630676},{"id":"54355233","wikidata":"https://www.wikidata.org/wiki/Q7162","display_name":"Genetics","score":0.0813513994216919}],"counts_by_year":[{"year":1989,"works_count":1,"oa_works_count":1,"cited_by_count":0},{"year":1991,"works_count":1,"oa_works_count":0,"cited_by_count":0},{"year":1996,"works_count":2,"oa_works_count":1,"cited_by_count":0},{"year":1997,"works_count":1,"oa_works_count":0,"cited_by_count":0},{"year":1999,"works_count":2,"oa_works_count":0,"cited_by_count":0},{"year":2005,"works_count":1,"oa_works_count":0,"cited_by_count":0},{"year":2006,"works_count":2,"oa_works_count":2,"cited_by_count":0},{"year":2008,"works_count":4,"oa_works_count":2,"cited_by_count":0},{"year":2009,"works_count":5,"oa_works_count":1,"cited_by_count":0},{"year":2010,"works_count":2,"oa_works_count":0,"cited_by_count":0},{"year":2011,"works_count":1,"oa_works_count":0,"cited_by_count":0},{"year":2012,"works_count":1,"oa_works_count":1,"cited_by_count":17},{"year":2013,"works_count":0,"oa_works_count":0,"cited_by_count":20},{"year":2014,"works_count":0,"oa_works_count":0,"cited_by_count":25},{"year":2015,"works_count":0,"oa_works_count":0,"cited_by_count":28},{"year":2016,"works_count":0,"oa_works_count":0,"cited_by_count":22},{"year":2017,"works_count":0,"oa_works_count":0,"cited_by_count":23},{"year":2018,"works_count":0,"oa_works_count":0,"cited_by_count":11},{"year":2019,"works_count":0,"oa_works_count":0,"cited_by_count":13},{"year":2020,"works_count":0,"oa_works_count":0,"cited_by_count":15},{"year":2021,"works_count":0,"oa_works_count":0,"cited_by_count":20},{"year":2022,"works_count":0,"oa_works_count":0,"cited_by_count":15},{"year":2023,"works_count":0,"oa_works_count":0,"cited_by_count":13},{"year":2024,"works_count":1,"oa_works_count":1,"cited_by_count":9},{"year":2025,"works_count":0,"oa_works_count":0,"cited_by_count":9},{"year":2026,"works_count":0,"oa_works_count":0,"cited_by_count":7}],"display_name_alternatives":["Kazuyuki KOYAMA","Kazuyuki Koyama"],"block_key":"k koyama","works_api_url":"https://api.openalex.org/works?filter=author.id:A5113597471","awards_count":0,"awards_api_url":"https://api.openalex.org/awards?filter=investigators.author.id:A5113597471","updated_date":"2026-11-11T13:02:13","created_date":"2016-06-24T00:00:00"}